[PATCH] Hugetlb: Copy on Write support

[linux-2.6] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 078cf920208af05e1e5d250dc7941ee134d02ada..795a050fe4714cb781dac80dcfc9d3e3c8f45275 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -201,13 +201,25 @@ static int shrink_slab(unsigned long scanned, gfp_t gfp_mask,
        list_for_each_entry(shrinker, &shrinker_list, list) {
                unsigned long long delta;
                unsigned long total_scan;
+               unsigned long max_pass = (*shrinker->shrinker)(0, gfp_mask);
 
                delta = (4 * scanned) / shrinker->seeks;
-               delta *= (*shrinker->shrinker)(0, gfp_mask);
+               delta *= max_pass;
                do_div(delta, lru_pages + 1);
                shrinker->nr += delta;
-               if (shrinker->nr < 0)
-                       shrinker->nr = LONG_MAX;        /* It wrapped! */
+               if (shrinker->nr < 0) {
+                       printk(KERN_ERR "%s: nr=%ld\n",
+                                       __FUNCTION__, shrinker->nr);
+                       shrinker->nr = max_pass;
+               }
+
+               /*
+                * Avoid risking looping forever due to too large nr value:
+                * never try to free more than twice the estimate number of
+                * freeable entries.
+                */
+               if (shrinker->nr > max_pass * 2)
+                       shrinker->nr = max_pass * 2;
 
                total_scan = shrinker->nr;
                shrinker->nr = 0;
@@ -355,7 +367,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping)
                res = mapping->a_ops->writepage(page, &wbc);
                if (res < 0)
                        handle_write_error(mapping, page, res);
-               if (res == WRITEPAGE_ACTIVATE) {
+               if (res == AOP_WRITEPAGE_ACTIVATE) {
                        ClearPageReclaim(page);
                        return PAGE_ACTIVATE;
                }